Feed mechanism.



F. H. HALSTEAD. -FEEQ MEcHAms-M. j APvPLIQATlUN FILED APR-8. ,1918. 4

Patented 8,1919.

Apr,

2 SHEETS-S Ffa.

I1 l @SW la www MLM tad-infine med UNITED STATES PATENT OFFICE.

FREDERICK n. H ALSTEAD, oE- Dos'roN, MASSACHUSETTS, ASSIGNCE y'ro EIVETT LATHE AND GEINDEE. CCMPANY, oEEANEUrL, MASSACHUSETTS, A CORPORATION or MASSACHUSETTS.

TotaZlj/whomn my concer/n: s

Be it known that I, FREDERICK H. HAL- sTEAD, a citizen of the United States, and a resident of Boston, county of Suffolk, and 5 -State of Massachusetts have invented yan Improvement in Feed Mechanisms, of which the following description, in connection with the accompanying drawings, is a specification, likecharacters on the drawings representing like parts.

his invention`-pertains to improvements in feed mechanisms, and more particularly, l y,though' not exclusively, to automatic feedi iariilsms for use in connection o s' M withiinachia t' l 'gif -sctidm partly in-elevation. on

the line 3--3 of Fig. 2; and r. F an vend elevation of thatl pormechanism shown in Fig. 2. have shown my improved latingygrinderinwhich 5 is the tool spindle land'G is the work chuck carried b v the work spindle. vThe work is shown as carried by an oscillatory support 7. While the tool '40 spindle 5 is carried by-a tool-head 8 which is adapted 'to be fed toward the work by movement along a feed slide 9, all in substantial accordance with my cofpending application.

The before-described mechanism constitutes one form of machine tool in which the work and tool are relatively traversed ,-while one is fed relative to the other by4 intermittent feed mechanism.

,In the preferred form of my invention selected for illustrative purposes. -the movable slide 9 is fed relative to the stationary slide 10 by a feed screw adapted to-be in terr'nittently'rotated by va ratchet 11. prefer- Specitibn ofi/Letters Patent.

p Application fue.; April s, 191s. Serial No. 227,408.

l L. i f e x ably through interina Late l.iieversuigg ing;v as shown in my (zo-pending applicax tion' before referred to.

. nut 15 adapted to abut vagainst astat fafgpreferred form ofL my in-1 'on which the ratchet11l s? ca herein shown as thea 'The cam element. 20ifs inyc'onnection mth an oscila 1 attached to the shaftt'l cam element 20 can be adjusted to an;7 de- 95 pin andv which is adapted to be spread by FEED MECHANISM.

Patented Apr.. 8, y1919.

ear-

The ratchet .11 may receive its movement from 'a pavvl 12, ivhich is preferably moved to and fro through a kpredetermined path of vmovement by any suitable mechanism, herein shown as the lever 13 corresponding to the similar lever in my-co-pending application, and vacting through "a reciprocav toryawl-carrnving roc'lffiltivhlch may be. andl 65 preferably is. provided 'with'` a- 'feed-limiting ioaery support 16 and to limit jtliefjd y ment of the pawl-carryifngli'd preferred form 4of mvk iii'ventio isr positively moved i bv the lever 13V and esili downward direction lov-the means or spring d erahly resilientlv urgeditoward t 11' b v a spring 18 carried b v tory ypaWl-carrying v irold"` I will now describe Ah of means for ,gradualiY p of rotar-'y feeding more f ratchet 11 by thefpaxvl crablv rotatablyr mountediso tha :t turn with the ratchet 11; Co-'aXialivitlrthashaftl 19 l preferablyrv afffcam'zaelement, 85

ecvefMQ-Oitlnav-ing a iirl-"fthe lfacefitheeof. i ref ei'ablvl ff rotatable d p referabl4k iperates with clutch m an s'oftha't aid' am element can be secure4 any desired point.

be. and preferably thread or track 21 cut-l 'ment 20 I preferabl provide apin 28 car- Where it isy desired'to provide a, const-antl 'riedby aA sliding, eetl-controlling bar 29.

. 'The "attachment between the 'pin 28 and feed-controlling bar 29 is preferably resili- --e11t,7being provided with a spring 30 sothat then-pin 28 may. beudisengaged from the 21.v The inner end/ofthe feed-controlling bar. y29 is preferablyV supported in cent .teeth of the rachet'll to limit and de.` I

of saidvelelnent may take any desiredform vlao lio

slidable' relation Ato astationary portion' of fthemachine by any. suitable guiding means,-

.herein shown asnthe ins 31 and 32 assing througha slot liin-tlie feed-.controlling bar The opposite end 'of the feed-control@ ling bar v,preferably 'carries a relatively thin pawlfengaging portion 35, adapted 'to be in-,4 Vtel-posed between the pawl 12 and the adjat'er'mi'ne the' point during' the operative stroke ofgthe pawl at which the point of :the pawl .shall yengage the teeth of the] 4ratchet 11, and, therefore. become operative frate'. of relatively slo'w feed followed byl a gradual reductiomthe feedflimiting nut 15 may be a-djusteddownwa-rdly on' thethrea'ds' of the pawl=carrying rod 14 so that a-comf I may, if desired, provide a constantrate of feed followed by 'a gradually diminishing feed by withdrawingl the y pawl' 28 from vthe parativelyjlimitedranfre of movement will Y be imparted to the pan/,2l

.groove 21 and setting the feed-controllin toturn said ratchet 11.' The pawl-engaging l' .portion ofthe pawl-controlling element-29 Amay beibeveled, as shown at 36, to provide a gradually decreasing feed,- or saidl portion Ilvs'hich'is necessary orgdesirable to provide any preferred rate of decrease of the feed.-

'lng movement' when the feed-controlling .bar

l'.29 .is moved toward the ratchetll by the .groove 21 "acting against 'the pin 2,8 as the .cam element 20 isrotated by the ratchet 1l. ,w-gglflhe operation of thepreferred form of.

invention is as follo'\vs:.-Where it is definredto provide a forward movement of the 4. feed-controlling'element 29 for each move- "ment of the ratchet 11 the pin' 28 is entered ina-the groove 21 and the machine is. started infbperatiOn, thereby causing the pawl-car rymg i'rod '14 to reciprocate and .turn the ra 11. As the ratchet 11v is turned it insaid cam-element, acting through the pin 28, pin-:hes the i:'eed-cont`rol'ling` rod 29 toward the 'ratchet 11 so that the thin pawlengaging portion of the feed-controlling .lement 29 'passesfbetween the pawl12 and theadjacent portion of theratchet 11, there-- by causingthe pawl to be held out of en- :gagement` with'the adjacentr teeth of the ratchet duringa portion of the forward or operative movement of the pawl 12. That portion of the stroke of the pawl which is thus rendered inoperative will be deter mined by thejcontour .of the surface 36 of the pawl-controlling element and, where a regularly beveled. edge 36 is'providecl, as

shown inthe drawing, th amount of lthe strole ofthe pawl which is rendered inoperative 1s progressively increased 'until, if

. desired, the entire stroke of thepawl 12 will have been renderedinoperative so that in' termittent rotation of the ratchet 11 will cease, thereby 'stopping relative' feeding', :movement of the work and tool. f

the cam element 20 and the groove. 21

vpresses against .rod 29 at anydesired point .with the end o the pin 28 resting on the higher portion .of the surface ofthe cam element 20'.'I 4The cam' 20 will not impart any longitudinal movement. to the' pawl-controlling element -29 until the pin 28 drops in Vthel groove-21 because of 'ratchet-'actuated rotation of the cam 20, after which the rate of feed will be progressively reduced and, if desired, en- -`tirely terminated by theautomatic feed-reduclng' mechanism in the manner previously described. v

I may, if desired, utilize the' longitudinal movement of the feed'controlling element 29 to operate traverse'stopping mechanism for stopping the relative traverse of work and tool at any desired point. This mayl be effected through mechanism resembling someywhatthat shown 'in my co-pending application above referred to," and connected to alever 37, whichis preferably provided with.

an .adjusting ,screw 38 and which functions in "a manner similar to the correspondinglever and adjusting screw of said co-pending lVhile Ihaveshown anddescribed a preferred lform ofone embodimentof my invvention, it will be understood that major changes involving omission, substitution, al-

teration and reversal of parts,' and' .even

changes in the mode of operation, may be.

made without departing'from the scope Aof my invention, which is -best deinedVin-,thc

followingclaims.-

Claims:

' In a machine tool, feed mechanisrnl comf prising; a pawl, means'forvimparting to said 1 pawl a toand-frq movement, a ratchet e'n- 'gaged by said pawl, and means driven` 'at a rate slower than thep'eriphery ofjs'aid ratchet andad'apted' to control the effective' peri-' odsV of engagement ot'said ypawlwith' said ratchet.4

2., In -a' machinetool, feed nmechanlsm'coinprising, in combination, a pawl, -means for imparting a to-and-fro movement `tofsafid pawl, a ratchetl wheel engaged by saidfpawl,`

. and means actuatedby movement ofj said ratchet, through interposed speed-reducing means, for progressively diminishing 'the periods 0f engagement .of said -pawl With said ratchet. I i

In a machine toolfeed mechanism comprising, in combination, a ratchet. a pawl engaging said ratchet. and `means movable tran.-:\'ersei}'v of the periphery ofpsaid ratchet A for progressivehv reducing the periods of effective engagement of said ratchet hy said pavrl.

i. In a machine tool. feed mechanism comprising. in combination, a ratchet, arpa-W1. a guard having an inclined edge-` and means `for progressiveljv interposing said guard between said paivl and the adjacentportion of the periphery of said ratchet, thereby to con trol the feeding movement. t

. In a machine tool7 feed mechanism comprising, in combination, a pawl, a 'ratchet' engaged thereby, 4ca in means driven by saidl ratchet, and a guard adapted to be moved A by said. cam means into interfering relation 'between said paivl and ratchet.

6. In amachine tool, feed mechanism comprising, :n combination, a ratchet, a pawl, a guard, means tor advancing said guard in.

a direction substantially parallel to the axisl -of said ratchetinto interfering relation between said paivl and ratchet, and means con- FREDERICK H. HALsTEai). 

